American Registry of Professional Animal Scientists (ARPAS) 2025 – 400 Free Practice Questions to Pass the Exam

Niacin, also known as vitamin B3, is classified as a water-soluble vitamin. This classification is important because water-soluble vitamins are not stored in the body to any significant extent; instead, they must be consumed regularly in the diet. They play essential roles in metabolism, particularly as coenzymes in energy production and in the synthesis of fatty acids and cholesterol.

The significance of niacin as a water-soluble vitamin means that deficiencies can develop more quickly than with fat-soluble vitamins, which are stored in the liver and fatty tissues. Good sources of niacin include meat, fish, poultry, enriched breads, and fortified cereals, highlighting its availability in a balanced diet.

In contrast, fat-soluble vitamins are stored in the body's fatty tissues and can lead to toxicity if consumed in excessive amounts. Minerals, while essential nutrients, are not classified as vitamins since they are inorganic elements. Amino acids are the building blocks of proteins and also differ significantly from vitamins in terms of biochemical function and classification. Understanding these distinctions helps in recognizing the nutritional roles of different compounds in animal and human health.